Etoxazole((RS)-5-tert-butyl-2-[2-(2,6-difluorophenyl)-4,5-dihydro-1,3-oxazole-4-yl]phenetol) is oxazoline compound, already known as insecticide or miticide (Japanese patent No. 3189011 and Japanese patent No. 3574785) and also known as ectoparasiticide on animals and acaricide for monophagous mites (Japanese patent application Laid-Open No. 2000-501695). However, when used outdoors, photostability of oxazoline compound cannot be said to be satisfactory. Therefore, selection of photostabilizer is important.
In Japanese patent application Laid-Open No. H09-59115, imparting photostability to oxazoline compound is mentioned. But it is very much a situation in which even by using one of UV absorber selected from cyanoacrylate-type, benzotriazole-type and benzophenone-type or by using two or more of them in combination as described in the document, satisfactory photostability cannot be achieved.
Also, it is known that photostability is obtained by using a combination of 2,2′,4,4′-tetrahydroxybenzophenone and 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol (Japanese patent application Laid-Open No. 2002-114604), but it relates to suppressing of decomposition of pyrethroid agent and does not mention about oxazoline compound. Moreover, combination use of UV absorber and antioxidant having the same base cannot achieve sufficient suppression of photodecomposition of effective ingredients in agrichemicals. It describes that in many cases, only additive effects can be obtained and in some cases where the actions of the agents oppose each other, even reduction in effect of each agent can be observed.